1. Field of Invention
The present invention is directed to a probe for measuring bends in a section of tubing. The probe is utilized to inspect tubing, such as utilized in a steam generator heat exchanger for detecting bends which occur in sections of straight tubing, for example during shutdown/refueling periods of a plant, indicating defects, damage and wear. The measurements made with the probe of the present invention are directly applicable to evaluation of tube stress levels to study stress corrosion cracking propensity of sections of tubing.
2. Description of Related Art
There exists many devices utilized for measuring the curvature and/or determining defects and wear in a section of tubing. Some devices use a plurality of fingers projecting radially from a cylindrical probe, which fingers ride on the inner surface of the section of tubing, to detect variations of the inner surface of the section of tubing as the probe is drawn through a length of tubing. The fingers in these previous devices are either mechanically or electrically coupled to an indicator and/or to a recording device for visually signaling to an operator that a defect is present. Other previously existing probes include a plurality of sections, with some sections serving as guide means, in which a mechanical or electrical detector senses variations in alignment between sections serving as guide means.
Various types of transducers have been utilized for detecting mechanical movement resulting from misalignment between guide sections of a probe. Also, strain gauges have been utilized for detecting movement of fingers contacting the inner surface of a section of tubing for detecting defects.